JP2691957B2 - Composite yarn for marine products and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite yarn for marine products, which is suitable for long lines used for tuna fishing and the like. More specifically, the present invention relates to a composite yarn for a marine material, which comprises a polyamide resin and a vinylidene fluoride resin.

[0002]

2. Description of the Related Art In recent years, required properties of fisheries materials such as synthetic resin fishing line such as tensile strength, knot strength, hardness, wear resistance,
As long castability, fish-finding detectability, visibility, transparency, and difficulty in curling become difficult, various proposals have been made in response thereto. For example, Japanese Patent Application Laid-Open No. 62-151129 proposes a fishing line made of a specific composite monofilament having a cross-sectional sea-island structure in which at least two kinds of heterogeneous synthetic polymers having different Young's moduli are used and a plurality of island components are scattered. Has been done. It is described that this improves fish-finding detectability and tying. Further, JP-A-62-149904 discloses a composite monofilament having a high knot strength, which is particularly suitable for fisheries and the like, and has a large flexibility in a sea component composed of a thermoplastic polymer having a low flexibility. It has been proposed that the island component composed of a thermoplastic polymer has a specific structure in which a plurality of island components are scattered near the center of the cross section of the filament. Although those relating to these proposals are intended for thick yarn diameters, the diameter is actually 1 mm or less.

By the way, a polyamide resin fiber having a large tensile strength capable of withstanding the weight of a giant fish has been used for a long line having a large diameter used for tuna fishing in the open sea. Approximately 5 for trunk lines stretched over the sea to a length of 500 m or more
It is hoped that the long lines set at 0 m intervals will be submerged in the sea as soon as possible so that the operation time can be shortened.

However, the conventionally used polyamide-based longline is as thick as about 1.8 mm (commonly known as No. 120 yarn) and has a large bending elastic modulus of about 90 kgf / mm ² and a large rigidity, and it is wound up for storage. If there is a "habit" that is curved or curved when you are doing it, there is a drawback that the specific gravity is as light as 1.14 and the "habit" that you once attached will affect the speed of sinking into the sea. . Therefore, even if the tensile strength is sacrificed to some extent, the specific gravity is large,
It has been desired to develop a long line having a bending elastic modulus of about 5 to 15% and a light transmittance in seawater of about that of a polyamide resin long line.

[0005]

DISCLOSURE OF INVENTION Problems to be Solved by the Invention The present inventors have conducted extensive research on fishing lines and composite yarns made of vinylidene fluoride resin having a relatively large specific gravity, and as a result, by adopting a specific production method, a polyamide type resin having excellent strength can be obtained. By combining a resin fiber and a vinylidene fluoride-based resin fiber that is slightly inferior in strength but can impart sufficient strength for practical use, it has a large diameter suitable for a long line that can meet the above demands. The present invention has been completed based on the knowledge that composite yarns for marine products can be supplied.

[0006]

That is, the first aspect of the present invention is that the polyamide resin, which occupies 90 to 70% of the volume fraction, forms a sea or sheath structure in the cross section of the composite yarn, and the volume fraction of 10 to 10 is obtained. A vinylidene fluoride resin occupying 30% is a composite yarn that forms an island or core structure of the composite yarn, and has a yarn diameter in the range of 1.0 to 3.0 mm and a tensile strength of 40 to 8
A ^second aspect of the present invention is a composite yarn for marine products, which has a total light transmittance in water of 85% or more and a parallel light transmittance of 15% or more in a range of 0 kgf / mm ² . A third aspect of the present invention is the use of the composite yarn as a long line, and the third aspect of the present invention is a melt composite spun from a composite nozzle that forms a polyamide resin and vinylidene fluoride resin into a sea / island structure or a sheath core structure. After cooling the thread below 30 ° C, 7
Characterized by performing the first stage stretching treatment of 3.0 to 4.5 times in a moist heat bath with hot water or steam maintained at a temperature of 0 to 100 ° C., and further performing the dry heat stretching treatment of 2.0 times or less. And a method for producing the composite yarn. Hereinafter, the present invention will be described in detail.

The polyamide resin used in the present invention may be any of those generally referred to as nylon, such as polycapramide, polyhexamethylene adipamide, polyhexamethylene sebacamide and polydodecamide, but vinylidene fluoride resin to be composited. In order to fully develop the strength of the vinylidene fluoride-based resin portion due to stretching due to the resistance of the contact surface while containing
It is preferable that the melt viscosity at 0 ° C. and the shear rate of 100 sec ⁻¹ is lower than that of the vinylidene fluoride resin by about 2000 poise. For example, polycapramide or capramide / hexamethylene adipamide copolyamide having such properties are preferable.

As the vinylidene fluoride resin, a vinylidene fluoride resin and a copolymer of vinylidene fluoride and another monomer are used. Examples of the copolymerization monomer include tetrafluoroethylene, trifluoroethylene, trifluoromonochloroethylene, hexafluoropropylene, ethylene, and the like, with preference given to hexafluoropropylene and ethylene. Among these vinylidene fluoride resins, vinylidene fluoride resin is preferable, and vinylidene fluoride / hexafluoropropylene copolymer resin is more preferable because it has flexibility and the crystallization speed becomes slow.

In the composite yarn of the present invention, the total volume fraction of the polyamide resin and the vinylidene fluoride resin is 100%, and the polyamide resin occupies 90 to 70% of the volume fraction, preferably 85 to 75%. On the other hand, the vinylidene fluoride resin occupies 10% to 30% of the volume fraction, preferably 15% to 25%. If the volume fraction of the vinylidene fluoride resin is 10% or less, the effect of increasing the specific gravity of the composite yarn is small, and if it exceeds 30%, the strength is greatly reduced and it becomes extremely difficult to maintain 40 kgf / mm ² or more.

The composite yarn of the present invention preferably has a core-sheath structure in which the vinylidene fluoride resin constitutes the core and the polyamide resin constitutes the sheath in the cross section of the yarn, but the vinylidene fluoride resin is the composite yarn. It does not matter even if it has a dispersed island structure of up to about ten. The core-sheath structure is preferable in order to maintain high transparency in water, and the sea-island structure is preferable in that it has a large flexibility and is hard to get habit.

The composite yarn of the present invention is prepared by melting polyamide-based resin and vinylidene fluoride-based resin using two or more extruders and introducing them into a composite spinneret having a core-sheath structure or a sea-island structure to form a known composite yarn. It can be manufactured by spinning by a spinning method and then stretching under predetermined conditions. When manufacturing the composite yarn of the present invention, the temperature condition during the first drawing is extremely important as a factor that influences the transparency particularly in water. At least tensile strength of 40 kgf / mm
^In order to maintain ² or more, a draw ratio of 3.0 times or more is required at first, but the drawing is performed in a hot water or steam moist heat bath, and the temperature during this drawing is in a relatively narrow temperature range of 70 to 100 ° C. Must be done in-house. When stretched at a temperature lower than 70 ° C, transparency is good, but peeling frequently occurs at the interface between the polyvinylidene fluoride resin phase and the polyamide resin phase, the tensile strength becomes unstable, and when stretched at a temperature higher than 100 ° C. Although the tensile strength is improved and the interfacial peeling is eliminated, the transparency in water is significantly reduced.

The stretching ratio in the first stage stretching is required to be 3.0 times or more, and if it is less than that, the strength is not developed. Also 4.
When stretched 5 times or more, not only the tensile strength is lowered, but also the peeling of the interface and the stretching unevenness of the polyamide resin are likely to occur, and the thickness irregularity of the yarn becomes extremely large. After the first-stage drawing treatment, the composite yarn for marine products of the present invention is obtained by further carrying out a dry heat drawing treatment of 2.0 times or less which is carried out with a usual polyamide resin.

The composite yarn for a marine material having a relatively large diameter obtained by the present invention is slightly inferior in tensile strength to a yarn of polyamide resin alone, but has a relatively large specific gravity and a small bending elastic modulus. Since it has become, the winding style is also improved. Furthermore, the light transmittance is almost the same as that of the polyamide resin. Since the composite yarn of the present invention has such characteristics, it is extremely suitable especially for long lines. Hereinafter, the present invention will be described more specifically with reference to examples.

[0014]

Examples (Example 1) Relative viscosity [(η _rel ): 1 g of a sample was added to 100% 98% sulfuric acid.
value measured at 25 ° C. using an Ostwald viscometer] 4.5 pellets of capramide / hexamethylene adipamide (6/66) copolyamide (PA) and an intrinsic viscosity of 1.4 dl / g 2 pellets of vinylidene fluoride / hexafluoropropylene copolymer resin (PVDF)
They were melted separately by two 35 mmΦ extruders, and the polyamide was spun from the same spinneret into a sheath-core type in which the sheath was made of polyamide and the vinylidene fluoride resin was made of a core. The spinneret has a hole diameter of 7.0 mm
Then, the composite weight ratio (polyamide / vinylidene fluoride resin ratio) was spun to 71.8 / 28.2, put into 5 ° C. water and cooled, and continuously 4.0 times in 90 ° C. warm water. The film was stretched and further stretched 1.4 times in 270 ° C. hot air. Furthermore, it is subjected to 5% relaxation heat treatment in a dry heat at 240 ° C., and the diameter is 1.8 mm.
The drawn yarn of was obtained. The composite cross-section ratio of this drawn yarn is 80/2
The specific gravity was 0 (polyamide / vinylidene fluoride resin ratio) and 1.26. This drawn yarn has excellent transparency, high strength and flexibility, and the yarn quality is 95.3% of total light transmittance in water, 33.1% of parallel light transmittance in water,
The tensile strength was 63 kgf / mm ² , the tensile elongation was 50%, and the flexural modulus was 82 kgf / mm ² .

(Examples 2 to 7) The same procedure as in Example 1 was carried out while changing the composite ratio, the draw ratio and the wet heat drawing bath temperature. The results are shown in Tables 1 and 2. In Example 7, a composite spinneret (pore diameter 7.0 mm) capable of forming a sea-island type composite system having 10 circular islands in the stretched cross section was used, and polyamide was used as the sea part and polyvinylidene fluoride was used as the island. Part was subjected to composite spinning. The distribution of 10 islands is 1 at the center of the thread cross section, 6 so that the center point of each island is a regular hexagon near the circumference, and the 6 islands and the center around the center island. Three islands were provided so that the distance between them and each of the islands was equal.

[0016]

[Table 1]

[0017]

[Table 2]

Comparative Example Only the copolymerized polyamide used in Example 1 was melt-spun and stretched in the same manner as in Example 1 to obtain a stretched yarn having substantially the same diameter.
As shown in Table 2, the drawn yarn has a specific gravity of 1.13 and the yarn quality is 94.4% in total light transmittance in water and 21.25 in parallel light transmittance.
0%, tensile strength 65 kgf / mm ² , tensile elongation 54%,
The flexural modulus was 93 kgf / mm ² .

[0019]

As described above in detail, although the present invention has a large yarn diameter and sacrifices tensile strength to some extent within a range that does not hinder, since it has a relatively large specific gravity, it easily sinks in seawater and has a bending elasticity. Provided is a composite yarn for marine products, which has a low rate and is hard to curl, and has a light transmittance in seawater of a polyamide resin longline. This composite yarn is extremely excellent as a longline.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-4-136212 (JP, A) JP-A-62-186732 (JP, A) JP-A-5-171512 (JP, A) JP-A-3- 172132 (JP, A) JP-A-3-123434 (JP, A) JP-A-62-151129 (JP, A)

Claims (3)

(57) [Claims] 1. A polyamide-based resin occupying 90 to 70% of the volume fraction forms a sea or sheath structure in the cross section of the composite yarn, and a vinylidene fluoride-based resin occupying 10 to 30% of the volume fraction is the composite yarn. Which is a composite yarn forming an island or core structure having a yarn diameter of 1.0 to 3.0 mm, a tensile strength of 40 to 80 kgf / mm ² , and a total light transmittance in water. 85% or more, parallel light transmittance 15%
The above is the composite yarn for marine products. 2. The composite yarn for marine products according to claim 1, which is used for long lines. 3. A molten composite yarn spun from a compounding nozzle for forming a polyamide-based resin and a vinylidene fluoride-based resin into a sea / island structure or a sheath-core structure is cooled to 30 ° C. or lower and then 70 to 100 ° C. The first stage stretching treatment of 3.0 to 4.5 times is carried out in a moist heat bath with warm water or steam held at the temperature of, and further the dry heat stretching treatment of 2.0 times or less is performed. 1. The method for producing a composite yarn for marine products according to 1.